<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title></title>
	<script src="itcast 2.js"></script>
</head>
<body>
	<input type="button" id="btn" value=" 点击 " >
</body>
<script>
	I( '#btn' ).toggle(function ( e ) {

		console.log( this );
		console.log( e );
		alert( 1 );
	}, function () {
		alert( 2 );
	}, function () {
		alert( 3 );
	});

</script>
</html>